Robot Framework 源代碼閱讀筆記 之二

上次走到了具體測試執行的地方，感覺缺乏一個全局觀，有點走不下去。

還是再回頭看看整個設計思路，所有的模塊文檔都可以從這裏訪問到：

使用文檔：

http://robotframework.org/robotframework/

接口文檔：

http://robot-framework.readthedocs.io/en/3.0.2/autodoc/robot.html

在看這些keywords之前先記錄一下對爲什麼要用keywords這種方式而不是傳統的編程方式的思考：

1. 有大師曰過，所有的編程抽象，本質上都是DSL，也就是最後會變成一種領域專用語言，任何我們調用的庫都是。所以keywords本質上也是一種DSL。

2. 作爲測試領域的DSL，好的keywords設計可以極大的降低測試的編寫門檻和開發效率

3. 內置的Keywords應該提供一種測試邏輯完備性，包括各種判斷和循環

4. kewords使用上由於是基於英文設計的，應該更符合英語使用者的思維，如果有相應的中文版本那就可以更方便中文使用者，當然可以自己開發中文版

Robotframework自帶的默認keywords和庫如下，如果要熟練使用，最好都能仔細看看，尤其是builtin的。

BuiltIn
Contains generic often needed keywords. Imported automatically and thus always available.
Collections
Contains keywords for handling lists and dictionaries.
DateTime
Supports creating and verifying date and time values as well as calculations between them.
Dialogs
Supports pausing the test execution and getting input from users.
OperatingSystem
Enables performing various operating system related tasks.
Process
Supports executing processes in the system.
Remote
Part of the remote library interface. Does not have any keywords of its own.
Screenshot
Provides keywords to capture and store screenshots of the desktop.
String
Library for manipulating strings and verifying their contents.
Telnet
Supports connecting to Telnet servers and executing commands on the opened connections.
XML
Library for verifying and modifying XML documents.

Builtin的keywords可以和應該能夠解決我們平時常用的測試邏輯，如果不行還能夠保持原生python語言的靈活性。用這個思路，看看大概有哪些。

首先提示了，大部分關鍵字都提供了對錯誤信息的支持，而且可以是HTLML格式的，目的應該是可以讓錯誤信息更醒目。然後說有些keywords是可以支持python的語句，會用eval執行。內置的keywords如下：

Call Method · Catenate · Comment · Continue For Loop · Continue For Loop If · Convert To Binary · Convert To Boolean · Convert To Bytes · Convert To Hex · Convert To Integer · Convert To Number · Convert To Octal · Convert To String · Create Dictionary · Create List · Evaluate · Exit For Loop· Exit For Loop If · Fail · Fatal Error · Get Count · Get Length · Get Library Instance · Get Time · Get Variable Value · Get Variables · Import Library · Import Resource · Import Variables · Keyword Should Exist · Length Should Be · Log · Log Many · Log To Console · Log Variables · No Operation· Pass Execution · Pass Execution If · Regexp Escape · Reload Library · Remove Tags · Repeat Keyword · Replace Variables · Return From Keyword · Return From Keyword If · Run Keyword · Run Keyword And Continue On Failure · Run Keyword And Expect Error ·Run Keyword And Ignore Error · Run Keyword And Return · Run Keyword And Return If · Run Keyword And Return Status · Run Keyword If · Run Keyword If All Critical Tests Passed · Run Keyword If All Tests Passed · Run Keyword If Any Critical Tests Failed · Run Keyword If Any Tests Failed ·Run Keyword If Test Failed · Run Keyword If Test Passed · Run Keyword If Timeout Occurred · Run Keyword Unless · Run Keywords · Set Global Variable · Set Library Search Order · Set Log Level · Set Suite Documentation · Set Suite Metadata · Set Suite Variable · Set Tags ·Set Test Documentation · Set Test Message · Set Test Variable · Set Variable · Set Variable If · Should Be Empty · Should Be Equal · Should Be Equal As Integers · Should Be Equal As Numbers · Should Be Equal As Strings · Should Be True · Should Contain · Should Contain Any ·Should Contain X Times · Should End With · Should Match · Should Match Regexp · Should Not Be Empty · Should Not Be Equal · Should Not Be Equal As Integers · Should Not Be Equal As Numbers · Should Not Be Equal As Strings · Should Not Be True · Should Not Contain ·Should Not Contain Any · Should Not End With · Should Not Match · Should Not Match Regexp · Should Not Start With · Should Start With · Sleep · Variable Should Exist · Variable Should Not Exist · Wait Until Keyword Succeeds

一一看過還是比較花時間，先跳過。

再大概過一下有哪些庫吧：

All packages

All robot packages are listed below. Typically you should not need to import anything from them directly, but the above public APIs may return objects implemented in them.

• robot package
• robot.api package
• robot.conf package
• robot.htmldata package
• robot.libdocpkg package
• robot.libraries package
• robot.model package
• robot.output package
• robot.parsing package
• robot.reporting package
• robot.result package
• robot.running package
• robot.utils package
• robot.variables package
• robot.writer package

robot package提供了命令行的調用：

• run(): Function to run tests.
• run_cli(): Function to run tests with command line argument processing.
• rebot(): Function to post-process outputs.
• rebot_cli(): Function to post-process outputs with command line argument processing.
• libdoc: Module for library documentation generation.
• testdoc: Module for test case documentation generation.
• tidy: Module for test data clean-up and format change.

robot.api對外的API都通過這個模塊暴露出來，包括：

• logger module for test libraries’ logging purposes.
• deco module with decorators test libraries can utilize.
• TestCaseFile, TestDataDirectory, and ResourceFile classes for parsing test data files and directories. In addition, a convenience factory method TestData() creates either TestCaseFileor TestDataDirectory objects based on the input.
• TestSuite class for creating executable test suites programmatically and TestSuiteBuilder class for creating such suites based on existing test data on the file system.
• SuiteVisitor abstract class for processing testdata before execution. This can be used as a base for implementing a pre-run modifier that is taken into use with --prerunmodifier commandline option.
• ExecutionResult() factory method for reading execution results from XML output files andResultVisitor abstract class to ease further processing the results. ResultVisitor can also be used as a base for pre-Rebot modifier that is taken into use with --prerebotmodifiercommandline option.
• ResultWriter class for writing reports, logs, XML outputs, and XUnit files. Can write results based on XML outputs on the file system, as well as based on the result objects returned by the ExecutionResult() or an executed TestSuite.

這些接口大概在開發自己的library的時候會比較有用吧。

robot.model package

Package with generic, reusable and extensible model classes.

This package contains, for example, TestSuite, TestCase, Keyword and SuiteVisitor base classes. These classes are extended both by execution and result related model objects and used also elsewhere.

robot.running package

Implements the core test execution logic.

The main public entry points of this package are of the following two classes:

• TestSuiteBuilder for creating executable test suites based on existing test case files and directories.
• TestSuite for creating an executable test suite structure programmatically.

It is recommended to import both of these classes via the robot.api package like in the examples below. Also TestCase and Keyword classes used internally by the TestSuite class are part of the public API. In those rare cases where these classes are needed directly, they can be imported from this package.

這個模塊是核心測試執行邏輯。有一個例子：

比如有個activate_skynet.robot文件內容如下

*** Settings ***
Library    OperatingSystem

*** Test Cases ***
Should Activate Skynet
    [Tags]    smoke
    [Setup]    Set Environment Variable    SKYNET    activated
    Environment Variable Should Be Set    SKYNET

對應的，如果不用robot去執行，可以用TestSuiteBuilder來讀

from robot.api import TestSuiteBuilder

suite = TestSuiteBuilder().build('path/to/activate_skynet.robot')

也可以用TestSuite的模塊直接build出來

from robot.api import TestSuite

suite = TestSuite('Activate Skynet')
suite.resource.imports.library('OperatingSystem')
test = suite.tests.create('Should Activate Skynet', tags=['smoke'])
test.keywords.create('Set Environment Variable', args=['SKYNET', 'activated'], type='setup')
test.keywords.create('Environment Variable Should Be Set', args=['SKYNET'])

還有一個執行的例子

result = suite.run(critical='smoke', output='skynet.xml')

assert result.return_code == 0
assert result.suite.name == 'Activate Skynet'
test = result.suite.tests[0]
assert test.name == 'Should Activate Skynet'
assert test.passed and test.critical
stats = result.suite.statistics
assert stats.critical.total == 1 and stats.critical.failed == 0

然後是生產report的例子

from robot.api import ResultWriter

# Report and xUnit files can be generated based on the result object.
ResultWriter(result).write_results(report='skynet.html', log=None)
# Generating log files requires processing the earlier generated output XML.
ResultWriter('skynet.xml').write_results()

這個例子有點矛盾，應該是先生產XML然後HTML吧

好了，今天到這裏，明天繼續，看看有沒有什麼新思路